Hurricane Sandy’s powerful winds and waves infused the long-polluted Gowanus Canal, named a Superfund site by the U.S. Environmental Protection Agency in 2010, with untold gallons of fresh water. But the storm raised concerns that the Gowanus’ toxins overflowed into the surrounding neighborhoods, presenting new health risks. The latest tests show that the canal already is back to its pre-Sandy level of pollution, according to the environmental group Riverkeeper.

WATER HAZARD: The Gowanus Canal overflowed during Sandy, raising concerns that the polluted waterway sent toxins flowing into surrounding neighborhoods. Reported by Amital Isaac. Shot and edited by Sarah M. Kazadi.